Manipulating canola growth to conserve soil water – Tamworth and Blackville 2012

Abstract

Key findings • Defoliation of canola just prior to stem elongation has the capacity to conserve soil water in the surface 90 cm, while water use differences between varieties can extend to at least 180 cm. • Defoliation resulted in no yield loss at the Tamworth site but significant losses at Blackville, which may be a function of lower starting water and plant population compared to Tamworth. • The application of the PGR treatment, Cycocel and Moddus, significantly increased yield by an average of 0.27 and 0.36 t/ha at Blackville and Tamworth, respectively. This yield increase was not due to increased soil water availability or a reduced canopy size and requires further investigation. • Neither of these PGR products are registered for use in Canola.